Refrigeration system with turbine drive for compressor



Oct. 4, 1966 w. T. OSBORNE v 3,276,226

REFRIGERATION SYSTEM WITH TURBINE DRIVE FOR COMPRESSOR Filed Oct. 8,1964 REFRIGERANT CONDENSER 23 AM CONDENSER INVENTOR.

WILLIAM T. OSBORNE.

ATTORNEY.

United States Patent 3,276,226 REFRIGERATION SYSTEM WITH TURBINE DRIVEFOR COMPRESSOR William T. Osborne, Syracuse, N.Y., assignor t0 CarrierCorporation, Syracuse, N.Y., a corporation of Delaware Filed Oct. 8,1964, Ser. No. 402,395

5 Claims. (31. 62-474) This invention relates to purging and balancingfluids in a refrigeration system and, more particularly, to separatingfluids mixed during operation of the system and returning separatedfluids for reuse in the system.

A heating and cooling system is discussed in my prior copending UnitedStates patent application for a Cooler, Serial No. 377,317, and filedJune 23, 1964. This system incorporates a steam driven turbocompressor,and the cooling capacity of the system is regulated responsive to theoutput of the turbocompressor which is regulated by blan-keting aportion of a steam condenser with noncondensible (refrigerant) vapor tovary the discharge pressure of the turbine side of the turbocompressor.Any leakage of steam or refrigerant within the turbocompressor is passedto the steam condenser and along with any other refrigerant entering thesteam condenser is mixed with water vapor therein, and a purge systempasses the valpors from the steam condenser to a cooler. The mixedfluids are separated in the cooler and the refrigerant is passed throughthe refrigerant side of the system and the power fluid is returned tothe power side of the system, for reuse in the system. Steam condensateis returned from the steam condense-r to a steam generator by means of asteam condensate pump, and a separate water supply pump is used foroperating the purge system and for passing the water power fluid fromthe cooler back to the steam power side of the system. Excessive watervapor in the cooler may reduce the efficiency of the cooler somewhatbecause it places an artificial load on the compressor. Furthermore, aplurality of water pumps is required, thus increasing the cost andcomplexity of the system.

It is a primary object of this invention to provide a new and improvedrefrigeration system and a method of providing refrigeration.

Another object is to provide a new and improved purging and balancingarrangement in a refrigeration system and a method of purging andbalancing a refrigeration system.

Another object is provision in a refrigeration system of new andimproved means and method for separating mixed fluids in the system andreturning at least one of the separated fluids for reuse in the system.

These and other objects of the invention will be apparent from thefollowing description and the accompanying drawing which is a flowdiagram of a refrigeration system illustrating an embodiment ofapparatus incorporating features of the invention.

The illustrated refrigeration system is preferably hermetic foreffectively containing fluids in the system and preventing ambient airfrom entering the system. Ihe system may be considered as having a powerside including a circuit for circulation of a power fluid, a refrigerantside including a circuit for the flow of a refrigerant fluid under theinfluence of drive means driven by the power fluid, with suitable meansfor regulating the capacity of the refrigeration system.

The invention will be described with reference to a preferred powerfluid, which is water, and a preferred refrigerant which isoctafluorocyclobutane, commonly referred to as C318 and having achemical formula C 'F These fluids are particularly preferred because oftheir relative immiscibility and because they are inherently 3,276,226Patented Oct. 4, 1966 highly stable and do not tend to decompose orchemically react with each other or other materials in the system, orcause or promote corrosion or undesirable by-p-roducts. Also, thisrefrigerant is a relatively noncondensible vapor at the temperatures andpressures at which the power fluid (water) condenses, as well as at theusual ambient atmospheric conditions of temperature and pressure;

However, other power fluids and refrigerants having the requiredchemical and physical properties may be utilized within the scope ofthis invention.

As is more fully described in the aforementioned patent application, thedrawing illustrates a refrigeration system incorporating aturbocompressor 11. A power side of the refrigeration system includes asteam generator 12 which passes steam through a steam supply line 13 toa turbine section 14 of the turbocompressor 11 for driving .theturbocompressor. From the turbine 14 the steam passes through a steamdischarge line 15 to a steam condenser 16 from which the resultantcondensate flows int-o a steam condensate chamber 17 defining a secondzone. From the condensate chamber 17 a steam condensate or water pump18in a steam condensate line 19 returns the condensate through a checkvalve 20 to the steam generator 12 for recirculation through the powerside of the system. A refrigerant side of the system includes arefrigerant compressor section 21 of the turbocompressor 11. Thecompressor 21 is driven by the turbine 14 for passing high pressurerefrigerant vapor through a high pressure line 22 to a refrigerantcondenser 23 from which the refrigerant condensate passes through arefrigerant condensate line 24 and flow metering device 24' and into asuitable cooler or evaporator 25 defining a first zone and having achilled water line including a chilled water bundle 26 flooded in liquidrefrigerant in the cooler for cooling chilled water circulated to a loadhaving a cooling requirement. From the cooler 25, refrigerant vaporreturns to the compressor through a suction line 27 for recirculationthrough the refrigerant side of the system. Means for controlling thecooling capacity of the system may be of any desired type, and in theaforementioned patent application capacity control is provided bycontrolled blanketing of a condensing portion of the steam condenserwith a noncondensible (refrigerant) vapor to reduce the condensingcapacity of the steam condenser below its maximum condensing capacity,thereby regulating the turb-ine steam discharge pressure whilepreferably substantially constant pressure steam is supplied to theturbine in order to regulate the compressor refrigerant output.Alternatively, the system capacity may be regulated as by inlet guidevanes on the compressor, or as shown in the drawing, by regulating theheat input to the steam generator 12, for example, as by a suitablesensor 28 on the chilled water line 26 which actuates a regulator 29 tocontrol the quantity of fuel and air delivered to a steam generatorburner 30.

The turbocompressor 11 is preferably provided with water lubricatedbearings 31, and a water supply line 32 branches off of the steamcondensate line 19 downstream of the water pump 18 for supplyinglubricant Water through a lubricant water line 33 to the turbocompressor191. The Water supply line 32 is provided with a heat exchanger 34 forcooling the water passing therethrough. Lubricant Water, and any leakageof steam or refrigerant which may pass suitable seal means 35 in theturbocompressor 11, passes through a drain line 36 and into the steamcondensate chamber 17. The condensers 16 and 23 and the heat exchanger34 are preferably provided with cooling tower water through a suitabletower water circuit, which as illustrated, includes a tower water inletline 67 from a suitable cooling tower'(not shown) and a tower waterreturn line 38 back to the tower.

Any refrigerant or other noncondensible vapor such as air in the povverside of the system passes into the steam condenser 16 from which it iswithdrawn by a purge system. The purge system includes a purge line 40opening into the steam condensate chamber 17 for withdrawing thenoncondensible vapor and any water vapor carried therewith and passingthese mixed vapors to a jet pump 41 which receives cooled impellingwater through an impeller Water line 42 branching off of the watersupply line 32 downstream of the cooling heat exchanger 34. The purgeline 40 has a check valve 43 to prevent reverse flow into the steamcondenser 16. The jet pump 41 discharges the mixture of impeller Waterand the noncondensibles into a separator chamber or vessel defining athird zone at a lower elevation than the steam condensate chamber 17 toprovide a static head therebetween. A suitably low temperature isprovided the impeller water by means of the heat exchanger 34 so thatwater vapor in the purge line 40 condenses and along with the impellerwater collects in a body of water 45 in a lower portion of the separatorchamber as the noncondensi'bles 46 discharged from the jet pump 41 riseto the top of the separator chamber 44 and are trapped therein. Theoperating pressures and temperature ranges in the separator chamber 4 4are such that the refrigerant remains in vapor form along with othernoncondensi bles such as air introduced into the separator chamber, thusseparating the water power fluid and the noncondensibles 46 in the upperportion of the separator chamber.

During a purging cycle, water from the body of Water 45 returns to thesteam condensate chamber 17 through a first water return line 50 and anormally open solenoid valve 51 in the line 50. As purging continues,the noncondensibles continue to collect in the chamber 44 and the watervolume in the chamber 44 is slowly displaced. When suflicientnon-condensibles 46 have collected to displace the water level down to afirst electrically actuated probe sensor 52, the solenoid valve 1 isactuated to closed position. A normally closed second solenoid actuatedvalve 52 in a refrigerant return line 53 between the upper portion ofthe separator chamber 44 and the cooler 25 is simultaneously opened tocommence an exhausting cycle. As water and noncondensible continue topass into the separator chamber 44 the level of the water in theseparator chamber rises and the noncondensibles flow into the cooler.After about thirty seconds, the water in the separator chamber engages asecond electrically actuated probe sensor 54 near the top of theseparator chamber to again open the solenoid valve 51 and close thesolenoid valve 52. The residual noncondensibles 46 in the separatorchamber 44 will expand slightly causing the water level to drop slightlywhen the valve 51 opens and the valve 52 closes and because of thestatic head between the steam condenser chamber 17 and the separatorchamber 44 the pressure in the separator chamber is now only slightlygreater than the pressure in the steam condensate chamber 17. Water frombody of water 45 flows from the separator chamber to the steamcondensate chamber until again after collecting suflicientnoncondensibles the water level in the separator chamber 44 drops belowthe first probe sensor 52 whereupon the cycle is repeated.

During cooling operation, the cooler 25 is normally at about 5 p.s.i.g.,and the steam condenser 16 is normally at about 27 Hg vacuum.

Refrigerant passing from the refrigerant condenser 23 through therefrigerant condensate line 24 and into the cooler 25 may carry somewater with it, and such water will normally fi oat atop the heavierliquid refrigerantin the cooler and collect in a relatively tranquilarea 54" from which it flows across a suitable weir 55, or the like, andinto a pool or sump of Water 56, as is more fully described in theaforementioned copending patent applica- Iti on. Similarly, any watervapor carried with the refrigerant vapor through the refrigerant vaporline 53 may condense and settle on the body of boiling refrigerant fromwhich it similarly passes into the pool of water 56.

In order to return water from this pool to the steam condenser 16, asecond water return line 57 connects the cooler 25 and the steamcondensate chamber 17 and is provided with a normally closed thirdsolenoid actuated shut-off valve 58 which is opened when the water level:of the pool engages an upper electrically actuated probe sensor 59 andis closed when the water level drops below a lower electrically actuatedprobe sensor 60. The differential in pressure between the cooler 25 andsteam condenser 16 forces the water into the steam condenser.

The system is particularly suited for high pressure machines having asteam operating pressure in the range of psig or greater since such asystem requires a high head pump 18 to handle the steam condensate andtherefore a greater pressure is available to operate the jet pump 41 forwithdrawing the noncondensibles from the steam condenser 16 andproviding suflicient force to purge the steam condenser during thestart-up of the system when the pressures throughout the system may bevery high, for example, 50 p.s.i.g.. The system is applicable for usewith many types of capacity control systems for example, a blanketingcontrol system, burner throttling control, inlet guide vane control or acombination thereof for maximum operating efliciency. The pumpingfunctions are combined in one basic pump, that is the water pump 18which provides lubricant water to the turbocompressor bearings 31, steamcondensate to the steam generator 12, and impeller water to the jet pump41 for operating the purge system, thus reducing the initial andmaintenance costs of the system. Furthermore, by providing steamcondensate to the jet pump 41, the impeller Water is almost entirelyrefrigerant free to avoid flashing and the jet pump may be relativelysmall since its efiiciency is greatly increased, and less lift isrequired from the steam condenser 16 to the separator chamber 44 than tothe cooler 25 which is at a higher pressure. duced into the cooler 25,thus providing better cooler boiling coeflicients, and effectivelyeliminating artificial compressor loading from water vapor on therefrigerant side of the system while permitting simplified and moreflexible cooler construction. The system is applicable for use withdirect expansion coolers.

While a preferred embodiment of the invention has been described andillustrated, it will be understood that the invention is not limitedthereto since it may be otherwise embodied within the scope of thefollowing claims.

I claim:

1. A refrigeration system comprising a power side operable forcirculating steam power fluid and including a steam condenser at arelatively low pressure and in circuit with a steam generator, and meansincluding a:

steam condensate pump for passing steam condensate from said condenserto said generator, a refrigerant side operable responsive to operationof said power side for circulating a refrigerant fluid having a lowerboiling point than Water and including a compressor, a refrigerantcondenser and a cooler at a higher pressure than said steam condenser,the compressor, the refrigerant condenser and the cooler being placed incircuit for the passage therethrough of said refrigerant fluid toprovide cooling during cooling operation of the system, said compressorbeing actuated by said power side and in communication therewith so thata mixture of power fluid and noncondensible fluid including at leastrefrigerant fluid are in said steam condenser, means for separating themixed fluids and returning at least one of the separated fluids forvreuse in the system and including a closed vessel,

,purge means including a jet pump connected to said Also, very littlewater is intropassed to said vessel, whereby the noncondensible vaporcollects above a body of water in said vessel, a water line having anormally open first valve between said vessel and said steam condenserfor passing the water from said vessel to said steam condenser, and arefrigerant vapor line having a normally closed second valve betweensaid vessel and said cooler for passing the refrigerant vapor from saidvessel to said cooler when said second valve is open.

2. A refrigeration system, comprising a refrigerant side operable forproviding cooling including a compressor, a condenser and a cooler, thecooler forming a first zone for receiving refrigerant fluid, a powerside for circulating a power fluid to operate said compressor and havinga second zone for containing mixed power and refrigerant fluids, andmeans for separating the mixed fluids and passing the separated fluidsfor reuse on their respective sides of the system including a third zoneproviding means for separating the mixed fluids, means for passing themixed fluids from said second zone to said third zone to separate themixed fluids, means for normally passing the separated power fluid tosaid power side until a low liquid level is reached in said third zone,and means for then passing the separated refrigerant vapor from saidthird zone to said first zone until a high liquid level is reached insaid third zone.

3. A refrigeration system comprising a turbocompressor, a power side forcirculating steam power fluid and including a steam condenser at arelatively low pressure and a steam generator in circuit for operatingsaid turbocompressor, and means including a steam condensate pump forpassing steam condensate from said condenser to said generator, arefrigerant side responsive to operation of said turbocompressor forcirculating a refrigerant fluid heavier than and having a lower boilingpoint than water and including the compressor of the turbocompressor, arefrigerant condenser and a cooler at a substantially higher pressurethan said steam condenser, the compressor, the refrigerant condenser andthe cooler being placed in circuit for the passage therethrough of saidrefrigerant fluid to provide cooling during cooling operation of thesystem, the compressor being actuated by the turbine of theturbocompressor and in communication therewith so that a mixture ofpower fluid and noncondensible fluid including at least refrigerantfluid are in said steam condenser, means for separating the mixed fluidsand returning at least one of the separated fluids for reuse in thesystem including a closed vessel at a lower elevation than said steamcondenser, purge means including a jet pump connected to said vessel fordischarging into said vessel and to said steam condensate pump forreceiving impeller water therefrom, means including a purge line betweensaid steam condenser and said jet pump, means for passing noncondensiblevapor and any water vapor carried thereby from said steam condenser tosaid vessel, means for providing a temperature to condense the watervapor passed to said vessel whereby the noncondensible vapor collectsabove a body of water in said vessel, a water line having a normallyopen first valve between said vessel and said steam condenser forpassing water from said vessel to said steam condenser when said valveis open, a refrigerant vapor line having a normally closed second valvebetween said vessel and said cooler for passing the refrigerant vaporfrom said vessel to said cooler when said second valve is open, andvalve operating means for opening said first valve and closing saidsecond valve at a high water level in said vessel and closing said firstvalve and opening said second valve at a water level below said highlevel.

4. A refrigeration system comprising a turbocompressor having waterlubricated bearings, a power side for circulating steam power fluid andincluding a steam condenser at a relatively low pressure and a steamgenerator in circuit for operating said turbocompressor, and meansincluding a steam condensate pump for passing steam condensate from saidcondenser to said generator and to said bearings to lubricate thebearings, a refrigerant side for circulating a refrigerant fluid heavierthan and having a lower boiling point than water and including thecompressor of the turbocompressor, a condenser and a cooler at asubstantially higher pressure than said steam condenser and in circuitfor the passage therethrough of said refrigerant fluid to providecooling during cooling operation of the system, the compressor beingactuated by the turbine of the turbocompressor and in communicationtherewith so that a mixture of power fluid and noncondensible fluidincluding at least refrigerant vapor are in said steam condenser, meansfor passing to said steam condenser the lubricating water from saidbearings and any leakage of steam or refrigerant within saidturbocompressor, means for removing said noncondensibles from said steamcondenser and separating the mixed noncondensible and power fluids andreturning the separated refrigerant and power fluids for reuse on theirrespective sides of the system including a closed vessel, purge meansincluding a jet pump connected to the vessel for discharging into saidvessel and to said steam condensate pump for receiving impeller watertherefrom, a purge line between said steam condenser and said jet pumpfor passing the noncondensible vapor and any water vapor carriedtherewith from said steam condenser to said vessel and including a checkvalve for effectively preventing reverse fl-ow into said steamcondenser, means for cooling the impeller water to condense the Watervapor whereby the noncondensible vapor collects above a body of water insaid vessel, a water line having a normally open first shut-off valvebetween said vessel and said steam condenser for passing water from saidvessel to said steam condenser responsive to the pressure differencetherebetween when said first valve is open, a refrigerant vapor linehaving a normally closed second shut-off valve between said vessel andsaid cooler for passing the refrigerant vapor from said vessel into saidcooler when said second valve is open, and means for closing said firstvalve and opening said second valve at low water level in said vesseland opening said first valve and closing said second valve at high waterlevel in said vessel.

5. A system according to claim 4 including means for collecting Water insaid cooler in a pool of water, a second water line having a normallyclosed third shut-off valve between said cooler and said steam condenserfor passing water from said pool to said steam condenser when said thirdvalve is open, and means for opening said third valve responsive to ahigh level of said pool to pass the water to said steam condenser andfor closing said third valve when the water level drops below said highlevel.

References Cited by the Examiner UNITED STATES PATENTS 677,845 7/1914Coleman 62501 X 2,852,922 9/1958 Neumann et al. 62500 2,931,190 4/1960Dubitzky 62-114 3,199,310 8/ 1965 Schlichtig 62502 X ROBERT A. OLEARY,Primary Examiner.

W. E. WAYNER, Assistant Examiner.

2. A REGRIGERATION SYSTEM, COMPRISING A REFRIGERANT SIDE OPERABLE FORPROVIDING COOLING INCLUDING A COMPRESSOR, A CONDENSER AND A COOLER, THECOOLER FORMING A FIRST ZONE FOR RECEIVING REFRIGERANT FLUID, A POWERSIDE FOR CIRCULATING A POWER FLUID TO OPERATE SAID COMPRESSOR AND HAVINGA SECOND ZONE FOR CONTAINING MIXED POWER AND REFRIGERANT FLUIDS, ANDMEANS FOR SEPARATING THE MIXED FLUIDS AND PASSING THE SEPARATED FLUIDSFOR REUSE ON THEIR RESPECTIVE SIDES OF THE SYSTEM INCLUDING A THIRD ZONEPROVIDING MEANS FOR SEPARATING THE MIXED FLUIDS, MEANS FOR PASSING THEMIXED FLUIDS FROM SAID SECOND ZONE TO SAID THIRD ZONE TO SEPARATE THEMIXED FLUIDS, MEANS FOR NORMALLY PASSING THE SEPARATED POWER FLUID TOSAID POWER SIDE UNIT A LOW LIQUID LEVEL IS REACHED IN SAID THIRD ZONE,AND MEANS FOR THEN PASSING THE SEPARATED REFRIGERANT VAPOR FROM SAIDTHIRD ZONE TO SAID FIRST ZONE UNTIL A HIGH LIQUID LEVEL IS REACHED INSAID THIRD ZONE.